Energy Efficiency

Improve air quality with high-volume, low-speed fans

HVLS fans move large volumes of air with reduced energy consumption

By Mark D’Agostino November 23, 2020
Courtesy: Hunter Industrial Fans

High-volume, low-speed (HVLS) fans are large industrial ceiling fans used in plants, facilities, manufacturing centers, distribution centers and other large buildings (see Figure 1). Designed with longer blade lengths than conventional fans, HVLS fans have diameters ranging from five to 24 feet (see Figure 2). The fans move large volumes of air with minimized energy consumption per square foot.

HVLS fans differ from traditional high-speed floor fans in several ways, including their reduced noise, minimized energy consumption per square foot and significant cost savings. HVLS fans can require less than $1 per day to operate. Also, HVLS fans spin at relatively low speed compared to residential fans, reaching a maximum speed of 200 RPM and a minimum speed of 71 RPM. For comparison, a residential fan spins at speeds of up to 230 RPM (see Figure 3).

With lower fan speeds and longer blades, HVLS fans move more air and provide complete air circulation throughout large spaces with high ceilings. They produce air columns that move toward the floor and are then pushed outward in a 360-degree direction throughout the workspace. The airflow created replicates a natural breeze, making it feel up to 10 to 12 degrees cooler.

Large ceiling fans aid in creating good air quality and in minimizing dust, fumes and odors. If air is circulated throughout an entire space, there’s less chance for it to stagnate. The desire for good air quality grew especially crucial in 2020 and will likely be a top priority for managers as they plan for 2021. A Harvard Business Review survey reported the number one workplace wellness perk employees most desired was air quality. Air quality received 58% of the survey vote, with the option for an onsite gym receiving only 16%.

Figure 1: High-volume, low-speed fan. Courtesy: Hunter Industrial Fans

Figure 1: High-volume, low-speed fan. Courtesy: Hunter Industrial Fans

Destratification in cold months

When it comes to HVLS ceiling fans, it’s natural that some people associate them with being used only in warmer months. However, while the fans help circulate air throughout a space to keep occupants cool, they also are beneficial during the winter months to keep employees warm.

Adequate heating is a challenge for facilities with high ceilings, which can mean large heating bills in the winter months. Because hot air rises (stratification), the warm air is trapped at the ceiling level and not on the ground floor where the employees work.

Hot air naturally rises to a facility’s highest point, but the thermostat is located at the occupant level. Therefore, the heating system will continue to work to reach the desired temperature at the occupant level. This inefficient process will continue overheating the ceiling, thus overworking equipment and adding to operation costs. According to the Commercial Buildings Energy Consumption Survey, heating costs account for more than 35% of a building’s annual energy consumption.

Air destratification with an HVLS fan recirculates the warm air trapped at the ceiling level down to the ground floor. It creates a productive work environment that can result in lower heating costs.

A Hunter Industrial Fan customer reported that after installing an HVLS fan, it saw their energy bill reduced by an average of $2,500 annually compared to before the fan was installed. HVLS ceiling fans are the most cost-efficient heating and thermal destratification method.

In the winter, operate the HVLS fans at a lower speed and reverse its direction to help with destratification without creating a draft.

Figure 2: Designed with longer blade lengths than conventional fans, HVLS fans can have diameters ranging from five to 24 feet. Courtesy: Hunter Industrial Fans

Figure 2: Designed with longer blade lengths than conventional fans, HVLS fans can have diameters ranging from five to 24 feet. Courtesy: Hunter Industrial Fans

Improving moisture control and safety

Air quality can deteriorate in the workplace through microbial contamination. This can consist of microbes, including viruses, fungi, bacteria, mold and other particles. These contaminants can cause many health issues in workers, including allergic reactions, infections and the contraction of viruses. OSHA links the existence of these contaminants to a high humidity environment that can be caused by factors such as water damage in the building, unattended spills and high-humidity indoor areas.

Managing moisture concerns through increased air circulation is one way to help dry liquids while dispersing and reducing humidity. An HVLS fan moves air consistently and at a higher velocity than traditional fans, resulting in faster floor drying times and improved overall air circulation, which leads to lower humidity levels.

Moisture containment helps keep employee accidents due to slips and falls to a minimum. The fans help maintain a temperate work environment, which reduces heat-related illnesses and accidents, such as fainting, short-term memory issues, dehydration and absenteeism.

Using an HVLS fan to manage issues with moisture and humidity offers additional safety measures not possible with floor fans, including the removal of visible cords and the ability to operate multiple fans from a single interface control. A single control allows users more granular management over the fans’ run times, speed, direction and more. Whether it’s moisture control or workforce safety, HVLS fans can help users achieve a lot more than just keeping people comfortable.

Creating effective ventilation

From improving air circulation and keeping harmful contaminants at bay to replacing internal air with fresh air from the outside, avoiding stale and stagnant air quality is vital to keeping a building and workforce healthy. The National Institute of Health (NIH) cites ventilation and air distribution as the number one way to maintain acceptable air quality, in turn reducing the chance that employee health could be compromised. Giving employees less stagnant and higher quality air lessens the chances of acute or prolonged illness, resulting in an increase in productivity and fewer employee sick days.

Increasing ventilation and air circulation not only improves comfort, employee health and well-being, it also directly correlates to enhanced safety in a time when it matters more than ever. Your employees are your greatest asset and keeping them healthy and safe is a top priority. An HVLS fan helps enhance facility safety and improves comfort by increasing the overall air movement throughout the entire area.

Figure 3: Fan features a direct-drive motor with a plug-and-play design. Courtesy: Hunter Industrial Fans

Figure 3: Fan features a direct-drive motor with a plug-and-play design. Courtesy: Hunter Industrial Fans

Purchasing an HVLS fan

In large facilities, managing air quality can be a challenge. There are many conventional options — exhaust fans, high-speed floor fans, swamp coolers — but these traditional routes often fail to provide comprehensive solutions. HVLS fans operate efficiently in conjunction with an HVAC unit or as a solo source of airflow if the space does not have a unit. As you evaluate purchasing an HVLS fan for your facility, a few things to consider are the installation process, required maintenance, the warranty, product features and specific benefits for your industry.


Mark D’Agostino
Author Bio: Mark D’Agostino is general manager and senior vice president of Hunter Industrial Fans.